Practice questions, with answers and explanations included

A method that returns the value of a private data member is called a:

What is the purpose of the setEnabled() method for a jButton?

Convert: 2 Bytes = ______ MB (Hint: use the conversion chain).

A method that allows controlled modification of a private data member's value (possibly with validation) is called a:

Differentiate between jTextField and jTextArea, and between jComboBox and jList.

Convert: 3 Bytes = ______ MB (Hint: use the conversion chain).

What is the main benefit of using getter and setter methods instead of allowing direct public access to data members?

Which Java data type would be most appropriate to store a person's age (a small whole number)?

Write an SQL query to display PrName and UnitPrice of products with unit price above 25000 from table GYM.

Once a data member is declared private, it can still be accessed directly from outside the class using the dot operator.

Which data type is used in Java to store a single character, enclosed in single quotes?

Write an SQL query to display PrName and UnitPrice of products with unit price between 15000 and 25000 from table GYM.

A constructor is called explicitly by the programmer using a special 'construct' statement.

What is the storage size of the 'int' data type in Java?

Write an SQL query to display PrName and UnitPrice of products manufactured by 'Fit Express' from table GYM.

What is the difference between a Class and an Object? Give an example.

Which operator is used to test whether two values are equal in Java?

Write an SQL query to display PrName and UnitPrice of products whose manufacturer name starts with 'A' from table GYM.

Why is a constructor used in a class?

Which logical operator returns true only if BOTH connected conditions are true?